Asked by Derek Quach on Jun 10, 2024

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The makers of a soft drink want to identify the average age of its consumers.A sample of 55 consumers was taken.The average age in the sample was 21 years with a standard deviation of 4 years.
a.
Construct a 95% confidence interval for the true average age of the consumers.
b.
Construct an 80% confidence interval for the true average age of the consumers.
c.
Discuss why the 95% and 80% confidence intervals are different.

Confidence Interval

A range of values that is used to estimate the true value of a population parameter with a certain level of confidence.

Standard Deviation

An index used to assess the extent of variation or scatter among data points.

  • Gain an understanding of the procedure for determining a confidence interval for a population mean.
  • Recognize the distinctions in confidence intervals when comparing different confidence levels.
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Eldar Deli?Jun 12, 2024
Final Answer :

a.
19.92 to 22.08 years (rounded)
b.
20.30 to 21.70 years (rounded)
c.
As the level of confidence decreases, the confidence interval gets narrower.